1. Field of the Invention
The present invention relates to curable compositions, the methods of making and using same, particularly in cationic electrodepositable compositions. More specifically, the present invention relates to curable compositions comprising blocked isocyanate crosslinking agents.
Brief Description of the Prior Art
Curable compositions containing blocked isocyanate crosslinking agents are known in the art. These compositions cure at temperatures of about 350.degree. F. over a period of 20 to 30 minutes. With the advent of energy conservation, however, lower temperature cure has been desirable. Hence, much work has been done to formulate curable compositions that cure effectively at relatively lower temperatures.
As is the case here, much work has been done in developing blocked isocyanate crosslinking agents which would aid in effecting lower temperature cure. Consequently, it has been found that proper selection of blocking agents for isocyanato groups of these crosslinking agents results in the formation of crosslinking agents that effect cure at relatively lower temperatures. By the present invention, novel compositions comprising crosslinking agents which can effect cure at relatively lower temperatures have been provided.